Component-Resolved Microarray Analysis Of Ige Sensitization Profiles Toculicoidesrecombinant Allergens In Horses With Insect Bite Hypersensitivity

Background Allergy to bites of blood-sucking insects, including biting midges, can affect both human and veterinary patients. Horses are often suffering from an IgE-mediated allergic dermatitis caused by bites of midges (Culicoides spp). With the aim to improve allergen immunotherapy (AIT), numerousCulicoidesallergens have been produced as recombinant (r-) proteins. This study aimed to test a comprehensive panel of differently expressedCulicoidesr-allergens on a cohort of IBH-affected and control horses using an allergen microarray. Methods IgE levels to 27Culicoidesr-allergens, including 8 previously unpublished allergens, of which 11 were expressed in more than one expression system, were determined in sera from 347 horses. ROC analyses were carried out, cut-offs selected using a specificity of 95% and seropositivity rates compared between horses affected with insect bite hypersensitivity (IBH) and control horses. The combination of r-allergens giving the best performing test was determined using logistic regression analysis. Results Seropositivity was significantly higher in IBH horses compared with controls for 25 r-allergens. NineCulicoidesr-allergens were major allergens for IBH with seven of them binding IgE in sera from > 70% of the IBH-affected horses. Combination of these top seven r-allergens could diagnose > 90% of IBH-affected horses with a specificity of > 95%. Correlation between differently expressed r-allergens was usually high (mean = 0.69, range: 0.28-0.91). Conclusion This microarray will be a powerful tool for the development of component-resolved, patient-tailored AIT for IBH and could be useful for the study of allergy to biting midges in humans and other species.